Decade Counter Question

[TheAppleMac]

I have a 4017 Decade counter with a clock input pulse form an astable of time period 1 sec. If I connect an output pin (the last one) to the reset (allowing the counter go back to the start) and an LED to that pin also, will the counter reset before the LED can come on for the full second? Or can the LED stay on for the second and then the chip resets? Thanks for your time

 

[ericgibbs]

I have a 4017 Decade counter with a clock input pulse form an astable of time period 1 sec. If I connect an output pin (the last one) to the reset (allowing the counter go back to the start) and an LED to that pin also, will the counter reset before the LED can come on for the full second? Or can the LED stay on for the second and then the chip resets? Thanks for your time

hi,
As soon as the pin goes high it will Reset back to '0', no 1 sec flash.
You could add a AC coupled transistor to the pin, so that it Resets on the trailing edge of the 1 sec.

EDIT:
Like this.

 

[Diver300]

I don't see why you are bothering to reset it after the last pulse. It does that itself, in that the next count after 9 is 0.

If you want to count up to smaller numbers, you connect the next output, the one that you don't want to come on, to the reset line.

For instance, if you want to have 4 outputs only, they would be 0, 1, 2 and 3. If you connect output 4 to the reset line, then on the next pulse after 3 you will get 4 for only a few microseconds before it resets to 0.

 

[OlPhart]

Put an AND on outputs 3 & 0 so binary 9 (1001) turns on the LED for as long as 9 is valid : 1 sec. <<<)))

 

[mbarazeen]

if you leave without connecting any out puts to reset and keep the reset at low/ ground, it will reset giving a 1 sec out on the said last pin. the counter is having an internal reset.

 

[TheAppleMac]

Hi, sorry this reply is a bit late.

All I wanted to do was to design some sort flashing sign or image for Christmas, and in order to repeat a certain sequence, I needed to reset the chip. Thanks to EricGibbs for clarifying this.

To the other replies, I did not want to use it mathematically, just to display a sequence of LEDs

 

[crutschow]

To the other replies, I did not want to use it mathematically, just to display a sequence of LEDs

Whether you use the counter in a mathematical application or not, you still need binary math to describe its operation.

 

[TheAppleMac]

*maths



hehehe.... only joking. But thanks, I see your point.

 

[crutschow]

*maths

hehehe.... only joking. But thanks, I see your point.

We Yanks use the abbreviation 'math" for mathematics as "I majored in math". I believe you Brits use "maths". Do you say "I majored in maths"?

 

[TheAppleMac]

Yup But to me, it seems like a pointless thing to argue about... There are many webpages filled with two goons just trading insults, trying to convince the other why they are right.... It is people like this who make me feel better about myself

 

[crutschow]

I don't want to argue about it, either.

The only reason I prefer "math" is because it rolls off my tongue easier than "maths".